1. Field of the Invention
The present invention relates to the deodorization of sludges emanating from sewage plants, and, more especially, to the deodorization of such sewage by treating same with an effective deodorizing amount of at least one alkyl or polyoxyalkylene ester of undecylenic acid.
2. Description of the Prior
Sewage treatment plants are notorious sources of malodorous pollutants, which originate in the effluents both upstream and downstream of the treatment facility.
Upstream of the plant, drains constitute sites of fermentation influenced by the effluent temperature, the velocity of the water, the type of sewage system, etc.
The odor emissions are not well retained within the treatment facility.
The reduction of the risks of emission is a primary measure in combatting objectionable odors and typically such measure entails:
(i) the elimination of volatile pollutants contained in the effluents;
(ii) the limitation of the phenomenon of formation of malodorous chemical compounds;
(iii) the limitation of the physical phenomenon of conversion of aqueous phases into gaseous phases.
Deodorization also typically entails treatment of the sewage, upstream of the sewage plant, by means of at least one of the following techniques:
(a) injecting hydrogen peroxide into the sewage; PA0 (b) injecting pure oxygen into the sewage; PA0 (c) injecting iron salts (ferrous sulfate complexing sulfides in the form of iron sulfide) into the sewage.
In actual fact, the principal sources of uncontrolled odors in sewage plants are associated with the formation of sludges.